The Curious Case of the Stubby Thumb

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A thumb was outstretched in the circle of sixth-graders. It had a most peculiar shape, being relatively thin and normal near the base, and then suddenly capped off with a bulbous, short tip, reminiscent of a slightly flattened pearl onion.

The thumb belonged to 10-year old me. And I was showing it off proudly among my bemused friends.

“See, the other one's like this too!” I stretched out its equally short and bulbous sister. Everyone gaped, laughed, and held the thumb up for inspection.

“You must've bitten your fingernails too often when you were little!”

“Did you jam your thumb playing basketball?”

Why, no, I was born this way. If you're like me, you probably fielded these questions in your youth and wondered whether anybody else in the world has thumbs like yours.

Wonder no more – these thumbs are known in scientific circles as brachydactyly type D, a type of thumb characterized by a shortened distal phalanx (the bone at the tip of the digit) – and we are about to plumb the history, prevalence, myths and genetic basis behind these thumbs.

Most people have a straight, upright thumb, with a nail bed equal to or longer than the nails on their fingers. Some people have a “hitchhiker's thumb” where the tip can bend back almost 90 degrees. Finally, a few people – from 0.10 to 3 percent of a population – have a shortened thumb, a feature colloquially known as club thumb, stub thumb, toe thumb, potter's thumb, hammer thumb and most unappealingly, murderer’s thumb. Fortunately the thumb has been christened neutrally by scientists as brachydactyly type D, so henceforth we shall stick with the designation BDD.

BDD was first characterized by fortune tellers practicing palmistry. According to Angelfire.com's page on Indian palmistry:

"The Murderer's Thumb Unveiled - The clubbed thumb was traditionally called the 'murderer's thumb' denoting the powerful temper of those who carried it. This thumb has a short first phalange (section) and is broad. The tip of the thumb is fleshy and the thumbnail is short and broad. According to those who know, people with clubbed thumbs [however] are strong willed and can control their emotions."

Such a description is rather more palatable than Palmistrylines.com's take:

"This thumb is in a shape of a club. People possessing this type of thumb are animalistic in nature and thought system. They bear brutality of Elementary type. They can harm or murder out of callousness. They lack premeditation and depth."

Ouch! This leads the meeker among the BDD carriers to wonder: why such a dark reputation among chirologists? For the record, chirologists are fortunetellers.

“When these [traits] started getting studied in the late 19th century … there was a push to link [physiological] traits with personality traits. There's no real scientific connection between BDD and any personality trait though,” said Dr. Nathaniel H. Robin, an active clinical genetics practitioner and professor at University of Alabama at Birmingham, who authored a paper on BDD.

BDD is so named because it is one of many traits of brachydactyly, the term given for shortened fingers and toes due to underdeveloped bones in hands and feet. For example, there is brachydactyly type A, where middle phalanges of one, several, or all of the fingers and/or toes are shortened; brachydactyly type B, where distal phalanges and nails of the fingers and/or toes are small or absent; and so forth up to type E. Usually brachydactyly is an isolated trait, meaning that it is not associated with other medical conditions and is generally harmless.

Contrary to what many people with BDD think, BDD “is a fairly common trait,” Robin said. It stays in the population because “it's a benign variant,” meaning it is neither advantageous nor detrimental to those that express the trait.

According to "Abnormal Skeletal Phenotypes," published in 2005 by Alessandro Castriota-Scanderbeg and Bruno Dallapiccola, two prominent radiologists, BDD occurs in 0.4 percent of whites and 0.1 percent of blacks in the United States, with a higher incidence in Israel (1.6 percent of Jews, 3 percent of Arabs) and Japan. In three-quarters of cases, BDD occurs bilaterally, which means it appears on both thumbs, while in the rest of the cases it only appears on one thumb, with the other thumb normal.

There is also a skew among genders. The pioneering human geneticist Julia Bell found in a 1951 study that 60 percent of those affected with BDD were female, while 40 percent were male. The geneticist Robert Stecher confirmed the preponderance for females in a 1957 study. The reason for this may be due to incomplete penetrance, a genetic term that means that a trait fails to express itself even though a person carries the necessary genes. In the BDD case, there is evidence to suggest that the trait has complete penetrance in females and incomplete penetrance in males. BDD is also an autosomal dominant gene, which means a person only needs to inherit it from one parent in order to express the trait.

In the past 10 years, scientists have been able to gain more insight into the genetic basis of BDD. In a 2003 study published in The American Journal of Human Genetics, researchers reported that two mutations in the gene HOXD13 may contribute to BDD.

So who has this trait? One of its most famous carriers is Megan Fox, an actress starring in the "Transformers" movies. She carries the trait on only one thumb, signaling incomplete penetrance. Due to her profile as a celebrity, discovery of her BDD thumb was highly publicized. Russian author and Nobel laureate Alexander Solzhenitsyn is also purported to have at least one BDD thumb. Other people with the trait include: Malin Akerman (US actress), Tory Mussett (Australian actress), Ashley Lynn Cafagna (US actress), and Kristen van Der Noot (Germany DJ and model).

The most speculated of BDD carriers, however, is past European royalty. Despite valiant efforts, I did not find which royals exactly are implicated, so we shall briefly suspend any curiosity along those lines. The European royalty had higher than normal incidence of inbreeding due to a desire to keep their bloodlines “pure.” This resulted in any abnormality or mutation, such as hemophilia, reappearing in higher rates in descendents, instead of being flushed out by a set of significantly different genes. BDD is claimed by some to be a marker of descent from European royalty. However, as BDD occurs all around the world and is both the result of inheritance and random mutation, this, if true, would only apply to a small subset of those with BDD.

“I have no idea” if BDD is linked to European royalty, Robin said. “It may be true – I have no idea.”

At least I have an idea whether mine is linked to European royalty - I'm 100 percent East Asian!

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Comments

Only my right thumb is a 'toe thumb' and I have grown up quite embarrassed by it. I always hid it when I felt like people could see it and I would go out of my way and do normal things differently so that nobody would see my thumb. My friends have always laughed at it and called it cute but I have not felt this way about it. After seeing this article and reading all of the comments I will no longer be ashamed of what my thumb looked like. My sister has both thumbs stubby and I met a friend who also has both thumbs. I have yet to find somebody with one like me but I will be on the lookout now that I know it's more common!

I'm a student and both my thumbs are BDD. After I read this article and the comments, I feel much better because I always thought no one else have these. My sibling would sometimes tease me because of them. I always hide it when I'm with my friends or anyone else except my family. And I'm still kind of scared that people will make fun of my thumbs because none of my friends or people I know have them. But I'm glad that I'm not the only one.

I always feel so incapable of stretching my clubbed thumb and i hate it, my thumb on my left hand is the only one clubbed. My uncle has both, and I only have one; we're the only ones in our entire family who has it :( lol. btw I'm mexican, does anybody know the percentage for my race to have it?

I hate them too - I only realised it was a condition this year (and I'm 54!). My family blamed it on my nail-biting. Mine only became noticeable in my mid-teens and now I'm more embarrassed about them than when I was younger. I hide them under my other fingers and love winter when I can wear gloves. People occasionally comment on them and I just say, 'Yeah,well...' and leave it at that. Maybe a plastic surgeon will come up with a cure for them when you're older.

My mother and I have BDD on both thumbs but mine are worse than hers. Think it was only actually noticed when I was about 7 years old. We've got European royalty in our lineage too so reading this just made my day :) I used to be a bit self-concious about them but now I love them. They're great at parties 'hey, have you seen my freaky thumbs' is the best ice-breaker I have! Anecdotally, I struggle with chopsticks but find typing, texting and piano easy. And the joints often click too, they're the only joints that click with regularity.

I've always had these thumbs, and always hated them, especially as a little girl. People usually didn't notice them at first, but when they did I'd get all types of questions. When my great grandmother first noticed them, she told my parents I needed to see the doctor. I've never met anybody else with these thumbs, but now I have a name for them and know there are more people out there that have them! I am guessing I got it from my mother, she is of Russian and middle eastern descent, but neither she or my grandmother have the thumbs. But who knows, maybe I have royal blood on my dad's side...

Hello! I have one clubbed thumb on my right hand. Growing up I thought I accidentally made my thumb that way with a "magic trick" I would do as a child. I thought I could squeeze all the tissue from one thumb and transfer it the other, then back to other thumb until I got stuck and all the tissue was on my right thumb! I was only tricking myself into this illusion because I later learned it is a genetic trait :). I never sucked my thumb or bit my nails either.

I have minor embarassment about it but usually people don't notice. the few times I've been asked I'm just matter of fact about it. Gladly, nobody has been cruel to me for it. My boyfriend that I have been with for almost 7 years only just noticed a couple years ago. I never tried to hide it either, haha. I have thin fingers othrwise and overall very small hands. It has only bothered me when I sometimes get tripped up typing text on a phone screen, although the newer touch screens are more accurate than in the past. Also, as others had mentioned, finding a bowling ball to fit since I'm right handed.

I'm from the United States, 27 years old. My dad is 100% Swedish and I'm not sure of the ancestry of my mom, she's white though. I'm very stereotypically Swedish-looking. I thought it was cool that Malin Akerman also has BDD since she's Swedish and I've convinced myself that I'm somehow related to her :). Nobody else in my family has BDD and I've never met anyone else who has it so it's neat to see all these comments, especially since they're more recent.

I still think it's so cool how rare this trait is.L and wanted to stop back and see any comments added.

I do keep my nails longer so it seems to make the different thumbs less noticeable. I actually used to get acrylic nails done at the salon and I'm sure the women were shocked at first and had never seen such a thing, but were probably more than anything irritated that is is more difficult to do a different shaped thumb. I was very particular about how it was done. I still haven't ever met anyone else with this condition. for many years I played the clarinet and piano, no issues. I'm an extremely fast typist on actual keyboards, people always comment on how crazy fast I type, haha. Thinking back, one girl in elementary school did comment in a disgusted voice "you're thumbs grow different." I just said "yep," didn't make a big deal about it, she never mentioned it again and nobody else ever noticed. If they did they didn't comment.

Again, nice to see you all here and be a part of the rare Clubbed Thumb Club!

I have club thumbs , my daughter has club thumbs - my grandaughters all have clubbed thumbs ! OK where did I get mine from as neither my parents or grandparents had clubbed thumbs ?????????? Is it inherited or just a mutation ???????????ZRzc

I have clubbed thumbs as well. however I only have it on my left hand, my right thumb is "normal". my parents and I always joke about how it looks like a toe ! I inherited this from my aunt on my mothers side. but my brother and my parents don't have it either.

I have a clubbed thumb, but only on my right hand. my parents and I always joke about how it looks like a toe ! I actually really hate my thumb because I mean I have one normal one to compare it too ! anyway I got it from my aunt on my moms side. :O

Thank you for providing so much inforation about our thumbs! I have two BDD thumbs. Normally people don't even notice. I do not remember ever being teased as a child. I've never had a problem with them! We are unique! :) :)

I have this! The thumb on my left hand is stubby. When I was a kid adults used to assume it was because I had bitten the nail, but I wasn't a nail biter at all! I've always been proud of them. Most people don't notice unless I put it next to the thumb on my right hand, I used to do this to freak people out! All of my fingers are quite short anyway (but not clubbed) which might make it less noticeable. A few years ago I met a girl at a festival who noticed my thumb and she had exactly the same thing and we took "thumb selfies". Anyways, today I found out that this has a name and that lots of people have it and it's a 'thing'. I can't believe how many were bullied for this - genuinely was never a problem for me at all and I love being able to surprise people with them, as most people have never seen one before :) I am of Russian, Jewish and Eastern European descent.

Both of my thumbs are like this. I'm the only one I've ever known to have them and was very self concsious about them growing up. Kids were actually pretty mean about it. And so was my family. I would hide them a lot. As a teacher, I would have kids comment on them. I just said "everyone is different" and moved on. I still hide them some today. I wish it didn't bother me as much as it does. I hate the terms 'toe thumb' and 'club thumb'. Yuck. I like BBD much better. I can't tell about my kids hands yet, but I'm praying they have regular thumbs. I wish I was of the mindset that they were "cute" like others here. I really do.

I've never met any one with thumbs like mine and am not really sure who in the family I inherited it from. It's very comforting to know I'm not alone but It's very alarming however that only 0.1 percent of black people have it, now I feel like an out sider all over again. I would love to run into someone with the same trait, maybe that would make me feel more comfortable. Great to see so many comments!!

Hi, I'm looking to speak to women aged 60 and over with clubbed thumbs to help my wife overcome severe health anxiety - she is obsessed that there is a link between clubbed thumbs and breast cancer in women in their 30s (my wife is now 30), and it is taking over our life. Please can anybody help? Thanks

I have two club thumbs, which my parents blamed on the fact I bit my nails when I was a child. My thumbs were normal until I was in my teens - this is quite common I've heard. I hate them. I always hide them by tucking them under my fingers as often as possible. No one else in my family as far back as anyone can remember has them, so I'm not sure why I have them. Texting is hard as my thumbs are too fat for the letters and I have never dared have a manicure in my life. My children are very rude about them - but they were a useful, if untrue, example to them not to bite their nails.... I have never met anyone else with this condition in my life. If I were given one wish it would be to have normal thumbs. I would love to have plastic surgery to make them look normal, if anyone could do this.

I had always thaught that when i was little i sucked my thumbs instead of having a dummy and thats why they are like this. But once I found out theat Megan Fox has the same thumb i couldent stop telling people when they asked me... so i am happy...And it makes me feel better that i know i am not the only one with these types of thumbs (0.10, 3% of the population) <---- makes me feel special

I have a club thumb on only my left hand. My right thumb is pretty normal. I believe I inherited it from my father's side of the family, although he does not have a club thumb. But I distinctly remember a member of his mother (my grandmother) coming to my grandmother's funeral, and she had them on both hands. I think it was my grandmother's sister. I also was told that traits like this, if passed from your father, will manifest on the left side of your body, while if the trait was from your mother, it will show up on the right side of your body. Case in point, my daughter got her club thumb on her right side. It is not nearly as noticeable as mine, it's liked a watered down version, but clearly different than her left thumb. So it all makes sense. I actually really have never fully owned my club thumb and I try to hide it all the time. I'm embarassed by it. But I am a typist for a living. The left thumb is the only digit not necessary in typing and it stays out of the way. LOL

My grandfather had clubbed thumbs on both hands, which were inherited by my mother. When I was 3 or 4 I became aware that my thumbs were different than my mother's and asked if my mine would look like that later. Neither my children or grandchildren have them.

I have BDD thumbs, though my right is a little longer than my left. I also have shorter fingers, thoough again my right hand is in general longer. might have to do with the fact i'm a rightie. only problems i've ever had are reach for instruments and hand crafts.

I was sitting here wondering about my thumb and decided to google it. My right hand thumb is a BBD thumb while my left hand thumb is normal. I had no idea that there was an official name for this condition and just thought I was weird. I told my kids that's what happens when you suck your thumb too much, lol, trying to get them to stop. I have always been a little self conscience about it and have never gone out of my way to point it out to people. I feel a little better knowing I'm not the only one out there.

I am a woman of Slavic and Germanic European ancestry -- I never knew there was a name for my short thumb, I just thought it made me unique and felt proud of it. I can't recall anyone ever teasing me about it when I was little. I prefer the term "Royal Thumb", which was the first term I ever heard used for this, by my chiropractor, who recognized the condition. My left hand has a normal thumb, my right hand has a Royal Thumb, so it appears I am a minority among this minority, one of the 25% who have just one short thumb, among the 0.10 - 3% of those who have the condition at all.

Gosh I have this condition on both my thumbs, and while reading this I realized my grandmother has type A, so I guess she's the one I got my BDD from ... wow. I've never really liked my thumbs, and I tend to tug them away and hide them in my palm (I'm a nail polish kinda gal) even though I've met at least 4 girls with the same condition. But when people ask if I was 'an experiment gone wrong', from now on I'll just say I have a muderer thumb ... that'll teach em.

I recently turned 50 and just stumbled across this article today. I have two BDD thumbs! Who knew there was a name for it. My sister has one. We have no knowledge of anyone else in our family tree that has these thumbs.(Dutch) Yes, I was teased by my brother and sisters and would hide them in school. In my early 20's I soon realized that we are all different. I stopped hiding my thumbs long ago and don't really care what others think. We're not that different...... just extra special. Thumbs up BDD ers!!

I also have clubbed thumb, only one, and my brother has both clumbbed thumbs. I never liked it. I know two more people with clumbbed thumbs and I think the precentage of people who has this is bigger than 0.1 percent.

my girlfriend has these so called stub thumbs. I tell you, those things work wonders...if you get my drift. fantastic article boss, couldn't have explained the lack of royalty affiliation any clearer. I'm deeply moved...over and over ;)

I have two identical thumbs. My father did to & he was of Scotish /English decent. Thank you for the info as I was always embarrassed by them. I had been told they were called Jones Thumbs. Other than myself & my Father no one else in my family has them.

Until I had my son I was the only person in my family who has the "toe thumb". My daughter does not have it but otherwise is my spitting image, while my son looks absolutely nothing like me what so ever and has my thumb! His is on the opposite hand as mine. When I was little my parents told me that when they made me they ran out of thumbs so they had to put a big toe on my hand so I could pick things up!

I never knew there was a name for my funny thumbs. Was terribly self conscious of them during elementary school. A distant uncle said they were from my paternal great great grandmother, I thought they were from thumb sucking. I do have relatives in England on my mother's side. Seems it is none of these just a trait you are blessed with. :)

Well I was watching the tv show Elementary and this characteristic was mentioned andso I just had to look it up. So nice to meet all of you. i always explained it as my left thumb humb is from my mother (Japanese) and the other from my fathe (half Irish and some other european mix). I like to show my thumbs off cause I think it is kinda cool. My father does have short hands and some curve to his fingers, so I guess he has a different type, he also didnt get great grades in school. I can type fast, worked as a transcriptionist for many years and my fat fingers (my doctor thought it was clubbing, a sign of cardiac disease and sent me to a cardioloogist who said it was normal) the fingers made it easy to play the clarinet. I was made fun of a little while in grade school but my hairy arms drew the attention first. Im in my 50's now and my arms dont seem so hairy and I love my thumb.

I am 51 (knocking on 52) and had no idea that this was a "thing" until I also heard it mentioned on Elementary (Season 3; Episode 10). In that episode, it's mentioned briefly but caught my attention. Off to the Internets I headed and found out there is a world of similiar thumbs! I'm the 5th of 6 children and none of my siblings or parents have these. I have always wondered (though not enough to search for an answer) why both of my thumbs were stubby and resembled other's toes. I'm 6''4" and have "pianist" fingers...I've always been able to palm a basketball and yet these thumbs of mine barely reach my index fingers when placed flat.

I have it on my left thumb but I alo have a right 4th toe that eems to be missing the entire middle bone, My mother has both thumbs and her father had it on everyone of his fingers and toes if I remember correctly....I never even noticed that my thumbs were different untill my little brother asked me why my thumb looked like a toe when I was about 12 or so and ever since when anyone aske me I told them It cot chopped of when I was little and the ame day I went to the hospital some other kid had his toe severed and the doctor put the wrong digit on the wrong person....Way too many gulible people out there....LOL

My 2 thumbs are inherited from my grandfather on my father's side. He immigrated from England and I was always told they were called cobblers thumbs. As with many others as a child I always hid them behind my fingers. I am happy to find there is an actual name for the thumbs I am now rather proud of.

I always called them hammerhead thumbs, so I appreciate the scientific term and additional information. I always thought it was a recessive allele since my brothers did not inherit BBD thumbs, so I appreciate learning it is thought to be a dominant trait. It is with interest that the article states there may be a royalty link. I have a pair of BBD thumbs, my father did, and he told me that some other ancestors had them. It may be totally coincidental, but my paternal grandmother was a Goodrich, and as such, my family are decendents of the aristocracy that owned Goodrich Castle in Wales, prior to William the Conquerer's invasion.

I do not have club thumbs but my father had 2 and they were double jointed. My aunt had 2 club thumbs. One of my daughters has 2 club thumbs and the other daughter has 2 club thumbs and a shortened finger. None of the grandchildren inherited this treat.

I played piano and clarinet for many years without difficulty. My only problems have been fitting my thumb into some bowling balls and texting on older style touch screen phones. iPhones are wonderfully accurate so it's generally not a problem for me. if the thumb registers the wrong letter the autocorrect fixes it.

My late mum had a thumb like this, and for a long time I thought it might have been a side effect of her brain bleed. I also thought she might be the only one like this. Neither my brother or myself has it and neither do our children. Then I began to notice that other people had such a thumb. It's never bothered me because it was just a part of my mum, who I loved very much, but now that I have found a explanation for the condition, it has cured my curiosity. Many thanks x

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